Matteo Clementi, 26, and Enrica Apollonio, 23, got stuck in traffic on their way to the airport on Wednesday.
By the time they arrived, the gate was closed and they were not allowed on board.
But they were having none of that.
They went to the next gate, forced open a security door, ran to the apron and began signaling to the pilots to let them on the plane but the engines were already running and the stairs had been removed.
The two were not allowed on board and were arrested by security staff.
Their defence counsel said that Apollonio's 23rd birthday was on Wednesday and that she had been looking forward to celebrating it with her family "but instead spent it in a cell".’
The couple was then fined 2,329 Euros (about 2,656 dollars) for their action.